NumberResearch Membership · Data 09/19/2026

Recent thousands-block assignments

0 blocks assigned in the last 30 days · from the daily NANPA thousands-block report, 09/19/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

Most carrier growth happens here, not at the prefix level: under number pooling, carriers receive individual 1,000-number blocks (e.g. 626-470-0XXX) within already-assigned prefixes. Assignments are initial assignments — the current serving carrier of individual numbers may differ due to portability.

Most active assignees, all time — NPA 203
LEVEL 3 COMMUNICATIONS, LLC - CT 200
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent thousands-block assignments
AssignedThousands-blockLast 4 digitsStatusAssigneeOCNRate centerState
2021-06-15 203-242-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 HUNTINGTON CT
2016-05-18 203-586-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WOODBURY CT
2014-10-03 203-802-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WATERBURY CT
2014-10-03 203-900-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 GREENWICH CT
2014-09-30 203-487-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 STAMFORD CT
2014-06-06 203-664-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 REDDING CT
2013-12-10 203-654-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NEW HAVEN CT
2013-10-09 203-403-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 RIDGEFIELD CT
2013-09-27 203-666-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 BRIDGEPORT CT
2012-12-19 203-680-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NEW HAVEN CT
2012-12-12 203-883-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 STAMFORD CT
2012-12-12 203-900-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 GREENWICH CT
2012-11-07 203-694-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 MERIDEN CT
2012-10-16 203-904-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NORWALK CT
2012-08-02 203-635-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WESTPORT CT
2012-07-05 203-309-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 DARIEN CT
2012-07-05 203-989-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 STAMFORD CT
2012-07-02 203-698-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 OLDGRNWICH CT
2012-05-30 203-779-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 MADISON CT
2012-05-30 203-951-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 MILFORD CT
2012-03-14 203-720-8XXX 8000–8999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NAUGATUCK CT
2012-02-15 203-529-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WILTON CT
2012-02-08 203-590-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 TRUMBULL CT
2012-02-08 203-635-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WESTPORT CT
2012-02-08 203-819-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WATERBURY CT
2012-02-08 203-941-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 SEYMOUR CT
2012-02-08 203-989-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 STAMFORD CT
2012-01-18 203-684-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NEW HAVEN CT
2011-12-29 203-286-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NORWALK CT
2011-12-29 203-456-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 DANBURY CT
2011-11-02 203-590-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 TRUMBULL CT
2011-08-03 203-774-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WALLINGFD CT
2011-07-20 203-802-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WATERBURY CT
2011-07-13 203-794-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 DANBURY CT
2011-05-05 203-779-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 MADISON CT
2011-02-23 203-538-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 HUNTINGTON CT
2011-02-04 203-403-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 RIDGEFIELD CT
2011-02-04 203-989-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 STAMFORD CT
2011-01-10 203-433-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 BRANFORD CT
2011-01-10 203-577-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WATERBURY CT
2011-01-10 203-916-6XXX 6000–6999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 BRIDGEPORT CT
2010-12-20 203-692-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 FAIRFIELD CT
2010-12-17 203-361-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NEW HAVEN CT
2010-11-17 203-584-9XXX 9000–9999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NEW HAVEN CT
2010-11-09 203-295-7XXX 7000–7999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 NORWALK CT
2010-11-01 203-423-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WILTON CT
2010-10-26 203-826-2XXX 2000–2999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 DANBURY CT
2010-10-26 203-916-4XXX 4000–4999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 BRIDGEPORT CT
2010-10-26 203-951-5XXX 5000–5999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 MILFORD CT
2010-08-02 203-429-3XXX 3000–3999Assigned LEVEL 3 COMMUNICATIONS, LLC - CT 4800 WESTPORT CT

Source: NANPA Thousands Block Assignment Report (All Regions, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.